Health care spending is projected to grow much faster than the economy

Health spending in the U.S. grew to $3.2 trillion in 2015, fueled partly by the expansion of health insurance to millions of people under the Affordable Care Act, according to a new estimate published in the journal Health Affairs.

The study also looks forward, projecting that through the next decade, national health spending will climb at 5.8 percent per year, on average, to encompass a fifth of the economy by 2025.

The report, compiled by a team of government actuaries, shows overall health spending picking up after a historic slowdown, but the growth remains lower than the nearly 8 percent annual growth in the two decades before the Great Recession.

The Obama administration — including the president himself in a recent essay — has credited the Affordable Care Act with keeping health expenditures in check. But economists remain uncertain whether the slowdown in spending is because of provisions of the law or might be explained by other factors.

In a statement, Andy Slavitt, the acting administrator of the Centers for Medicare and Medicaid Services, pointed to the health care law’s role in tempering growth: “The Affordable Care Act continues to help keep overall health spending growth at a modest level and at a lower growth rate than the previous two decades,” he said.

But a recent editorial by two economists published in the Journal of the American Medical Association was skeptical of the idea the law could be credited with the slowdown in the growth of spending — and noted an array of future challenges.

“This pressure on health care cost increases is not likely to moderate. Experts expect a wave of new medicines and devices, including immunotherapies in oncology, breakthrough treatments for Alzheimer’s …